Typically, an electronic system includes a number of integrated circuit chips that communicate with one another to perform system applications. Often, the electronic system includes a controller, such as a micro-processor, and one or more memory chips, such as random access memory (RAM) chips. The controller communicates with the memory to store data and to read the stored data.
The RAM chips can be any suitable type of RAM, such as dynamic RAM (DRAM) including single data rate synchronous DRAM (SDR-SDRAM), double data rate SDRAM (DDR-SDRAM), graphics DDR-SDRAM (GDDR-SDRAM), low power SDR-SDRAM (LPSDR-SDRAM), and low power DDR-SDRAM (LPDDR-SDRAM). Also, the RAM chips can be any suitable generation of memory including fourth generation DDR-SDRAM (DDR4-SDRAM), fifth generation GDDR-SDRAM (GDDR5-SDRAM), and higher generations of memory. Usually, each new generation of memory operates at an increased clock speed and/or an increased data rate from the previous generation.
In some existing electronic systems, a controller regulates the interface voltage of the controller and a memory based on a current mode of operation of the system. For example, some systems use dynamic voltage scaling (DVS), which involves scaling voltages down for lower power modes and scaling voltages up for higher power modes. DVS is typically performed in combination with a frequency change. Thus, when the voltage is scaled down, the frequency is also scaled down, and when the voltage is scaled up, the frequency is also scaled up.